Two new dimeric carbazole alkaloids, clausenawallines A and B, were isolated from the roots of Clausena wallichii. Their structures were elucidated by spectroscopic methods. Clausenawalline A was evaluated for its biological activities [anti-malaria (IC50 2.46 lg/mL), anti-TB (MIC 12.50 lg/mL)] and cytotoxicity against three human cancer cell lines [KB (IC50 7.87 lg/mL), MCF7 (IC50 25.43 lg/mL), and NCI-H187 (IC50 10.97 lg/mL)].